Vacuum tube socket



Sept. 15, 1931. w, J MURDQCK 1,823,331

VACUUM TUBE SOCKET Filed Dec. 5. 1927 INVENTOR A'I TORRLYS Patented Sept. 15, 1931 UNITED STATES PATENT OFFICE WILLIAM J. MURDOGK, OF CHELSEA MASSACHUSETTS, ASSIGNOR TO HAZELTINE COR- PORATION, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF DELAWARE VACUUM TUBE SOCKET Application fl1ed December 5, 1927; Serial No. 237,748.

This invention relates to vacuum tube sockets. g

The old fashioned vacuum tube socket having a cup-like receptacle to receive the 5 base of the tube and provided with a bayonet notch for engaging the pin on the side of the tube base has become quite generally superseded by a later type of socket which does not include such a receptacle for receiving the base of the tube. In this latter type of socket there are provided, generally, four small apertures each of which is intended to receive a particular one of the four contact prongs of a tubethe arrangement being such that the tube cannot be effectively engaged with the socket in any but the correct way. Sockets of this type have some distinct advantages; but in manyinstances, especially in radio sets where the sockets are not particularly accessible on account of the crowding together of the apparatus for the purpose of .attaining compactness, there has been, heretofore, one outstanding disadvantage in that it was much more difiicult to insert the tubes than was the case with the old fashion sockets. This difficulty arose from the necessity of getting all the contact prongs of the tube in .line with their respective socket apertures simultaneously before the prongs could be inserted therein. To do this involved not only turning the tube so as to bring each prong into proximity to the cor-' responding socket aperture, butrequired at the same time that the tube be centered with respect to the socket. .While this is not a diflicult thing to do when the socket is clearly visible and there is ample space, it is, on the other hand, quite difiicult when the socket is not clearly visible or where there is not su'flicient space to allow easy manipulation of the tube. For example, in many of the modern radio receivers the vacuum tube sockets are enclosed within metal shields there being openings provided in the shields to permit insertion of the vacuum tubes. 'These openings must, of course, be made large enough to-permit the vacuum tube to pass through, but for electrical reasons they are not usually made any larger than is necessary. Under such conditions, there is obviously very little finger room and, consequently, it is quite difiicult to manipulate the tubes into their sockets.

The present invention has for its object tocremove or at least greatly alleviate the above mentioned difficulty. This is accomplished by the provision of means for initially centering the tube when it is brought into engagement with its socket so that all that is necessary thereafter is to turn the tube until the contact prongs find their proper apertures in the socket-there being no effort required on the part of the person inserting the tube to keep it centered in respect to the socket as it is being turned.

As will be pointed out in'connection with the detailed description which follows, this provision obviates practically all of the difiiculty hitherto involved in getting the tubes into their sockets.

In the accompanying drawings wherein one of the preferred embodiments of the invention is illustrated:

Fig. 1 is a fragmentary top view of a vacuum tube supporting strip showing three sockets incorporated therein;

Fig. 2 is a bottom view of one of the sockets illustrated in Fig. 1; and

Fig. 3 is a cross-sectional view taken along the line 33 of Fig. 1 and showing, in addition, the base portion of a vacuum tube with its contact prongs engaged with a socket.

The structure illustrated comprises an elongated channel-shape metal strip 1 to the top of which is secured a flat elongated strip or plate of insulating material 2, such as hard rubber or bakelite. The strip 1 and plate 2 each have any desired number of spaced openings at convenient distances apart depending upon the desired separation between the vacuum tubes. The openings referred to in the supporting strip 1 are desig 'nated by reference numeral 3 while those in the insulating plate 2 are designated by reference numeral 4. To the underside of the strip 1 at each of the openings 3-there is attached a circular disc 5 of insulating ma terial. Each of the discs 5 is provided with four small apertures 6, 7, 8 and 9. These apertures are spaced and positioned to correspond with the contact prongs of a vacuum tube of the kind which the socket is intended to receive. In order to prevent the vacuum tube being inserted in the socket in the wrong way, the contact prongs are sometimes made of two difi'erentdiameters. Another way of accomplishing the same purpose, however, is to have the contact prongs spaced unevenly and the corresponding apertures in the socket likewise spaced unevenly. Either of the expedients mentioned will accomplish the same result. For the present purpose there will be considered only the case where two of the contact prongs of the vacuum tube are of one diameter and the remaining two of another diameter and, correspondingly, the socket apertures for receiving these prongs are of two different diameters. As illustrated in Fig. 1 the aper-.

tures 6 and 7 are of smaller diameter than the apertures 8 and 9. Since each of these apertures is made just large enough to pass its particular contact prong it is manifest that a vacuum tube can be inserted only in one particular way, which is the correct way.

The strips 1, plate 2 and discs 5 are secured together by means of metal eyelets vide electrical connections. Each of the conw tact springs 11, 12, 13 and 14 is suitably mounted and provided with soldering terminals for connection to the electrical circuits.

. An outstanding feature of novelty in this prongs do not come immediately into line with their respectively associated socket apertures, and it is, for that reason, usually necessary to rotatethe tube until the contact prongs find their corresponding apertures. With the tube held substantially on center with the socket, as herein described,

the task of inserting the tube is greatly sim- In Fig. 3 there is shown the base portion of a tube indicated by reference numeral 15,-together with two of its contact prongs asaassi 16 and 17 which are shown inserted through their respective socket apertures and in engagement with their associated contact SpIlIlgS.

This invention is not in any sense limited to the particular structure herein described, but on the contrary contemplates,,broadly, the idea of a Vacuum tube socketprovided with a recess, or its equivalent, whereby the contact prongs are initiallycentered, at least approximately, preliminarily to their insertion in their respective socket apertures.

As an alternative equivalent arrangement there could be provided, instead of the circular recess designed to circumscribe the contact prongs, a circular projection of a diameter which could be inscribed between the contact prongs and which would function in much the same way as the recesses hereinbefore described to center the contact prongs preliminarily to their insertion in the socket apertures.

I claim:

1. In a vacuum tube socket structure, a metallic supporting strip, a plate of insulating material secured to one side of said supporting strip, said plate of insulating material having a circular opening of a diameter suitable to closely circumscribe the contact prongs of a vacuum tube, said metallic supporting striphaving an opening larger.

than and substantially concentric with the opening in said plate, a member of insulating material attached to the other side of said metallic supporting strip and disposed opposite said opening therein, said member having a plurality of apertures each of which is designed to receive only a particular one of the prongs of a vacuum tube, and contact springs carried by said member, each of said contact springs being adapted to engage one of the contact prongs of a vacuum tube. i

2. A socket structure adapted to mount vacuum tubes of the type having a plurality of diametrically opposite contact prongs,

said structure comprising a flat insulating plate having a plurality of holes therein,

each hole being of a diameter slightly great-' er than the greatest distance between two diametrically opposite contact prongs of said vacuum tubes, a metallic strip beneath said plate and having holes concentric with the holes in said plate, flat insulating discs one of which is secured to the under side of said strip beneath each hole, each disc having a dimension greater than the diameter of the hole beneath which it is secured whereby the edge of each hole in said plate serves to guide the prongs of the vacuum tube preliminarily to their insertion in said roe apertures, contact springs secured to the under side of said discs adjacent said apertures for making electrical connections with the prongs of said. vacuum tubes, and means securing together said plate, said strip, and said discs, whereby said structure is rigidly supported by said metallic strip.

3. A socket structure adapted to mount vacuum tubes-of the type having contact prongs, which includes a metallic supporting structure having an opening therein of a diameter greater than that of the area occupied by the prongs of said vacuum tube, an insulating member secured to said structure and having a circular opening therein of slightly less diameter than that of the first-mentioned opening, and so positioned relative to the'opening in said supporting structure as to prevent contact of the tube with said supporting structure, a second insulating member also secured to said structure, in line with said openings, apertures in said last-mentioned member for selectively receiving the prongs of a vacuum tube, said apertures being of such dimensions and arrangement that the vacuum tube may be mounted in one position only, and contact springs secured beneath said members adjacent said apertures for making electrical connections with the prongs of the vacuum tube.

4. A socket structure adapted to mount vacuum tubes of the type having a plurality of diametrically opposite contact prongs, such structure comprising an inverted channel-shaped metal supporting member having a plurality of holesin the top thereof, each hole being of a diameter tocircumscribe the contact prongs of a vacuum tube, two fiat insulating members secured to said metal supporting member adjacent each of said holes, one of said insulating members having a hole therein of less diameter than the hole in said supporting member, yet greater than the diameter re uired to circumscribe the prongs of the tu e, and the other of said insulating members having apertures for selectively receiving the prongs of the vacuum tube whereby said vacuum tube may be mounted in one position only, said insulating members being secured to said supporting member in such a position as to prevent contact of a tube mounted in said socket with the supporting member, and contact springs adjacent said apertures for making electrical connections with the prongs of the respective vacuum tubes whereby the mechanism and current-carrying portions'of said socket structure are substantially enclosed within said metallic support.

a plurality of apertures for selectively re- I 5. A socket structure adapted to mountvacuum tubes of the type having contact ceiving the prongs of a vacuum tube, operatively disposed relative to the openin in said first-mentioned insulating mem er, whereby the edge of said opening serves to guide the prongs of the vacuum tube preliminarily to their insertion in said apertures, contact springs secured to the underside of said last-mentioned insulating member adjacent said apertures for making electrical connections with the prongs of said vacuum tubes, a metallic supporting structure, and means securing said insulating members to said. metallic supporting structure adjacent a hole therein for permitting the insertion of the prongs of the vacuum tube therethrough, said insulating member being so disposed relative to said supporting structure as to prevent the contact of the prongs of said tube with said structure while partially inserted within said apertures.

In testimony whereof I afiix my signature.

' WILLIAM J. MURDOCK. 

